The field of the invention is monitoring movement of an individual. More particularly, the invention relates to obtaining and analyzing data of exercises of an individual using non-contacting equipment.
The importance of physical activity is widely accepted, with overwhelming evidence pointing to the fact that regular exercise can help lower excess weight, reduce disease risks, and improve overall health. With increasingly sedentary lifestyles, maintaining regular workouts continues to be a challenge for many people. As a result, a number of tools and devices have been developed in recent years to quantify and track personal activities. Such devices can be used to motivate individuals to adhere to specific workout regimens, as well as provide valuable information to health and fitness professionals to identify the most beneficial course of action. In addition, such tools can enable study of the impact of specific activities on disease.
Assessment of physical activity has been traditionally based on self-reporting, and more recently on portable or wearable electronic devices. With self-reporting, various databases listing activity information obtained from population studies have been used to estimate energy expenditure during particular exercises. This approach is burdensome, subjective and prone to human error. With the advent of smartphones and other personal devices, personalized tracking of physical activity has become easier. Although such portable or wearable devices, fitted with a number of physical sensors, such as accelerometers and GPS trackers, offer distinct advantages in estimating physical activity level compared to self-reporting, they also have drawbacks.
Specifically, GPS tracking methods are limited to certain outdoor activities, such as running, cycling or hiking. On the other hand, accelerometer-based tracking methods are sensitive to how they are utilized, for instance, whether carried in a pocket or worn on an arm. They also require accurate algorithms for determining true energy expenditure, and differentiating non-exercise induced movements, such as driving or riding a bus. More importantly, many of the above-mentioned technologies cannot be applied to many common physical activities, including popular workouts (e.g., push up, yoga and weight lifting), as well as housework activities, and so forth. In addition, most wearable devices determine complex human body movements based on measurement with a single sensor at a particular location of the body (e.g., wrist), which can result in a number of false readings. Moreover, a device worn on a wrist, for example, cannot distinguish between bicep training and say eating a potato chip, since both activities involve similar arm movement.
As an alternative to wearable devices, imaging-based systems, relying on radio waves and optical imaging, have been developed to provide information for determining energy use during physical activity. Although these systems rely on sensors not directly in contact with an individual, in order to accurately track body movement, special markers placed at strategic locations, such as joints, must be worn. This makes use of imaging-based systems inconvenient for most people. In addition, such technologies have focused primarily on physical activities involving large center-of-mass movements, such as walking or running. By contrast, many common indoor workout routines, including push-ups, sit-ups, jumping jacks, and squats, involve small or subtle body movements (e.g., arms, legs and head), and also often upward movements against gravity, which are hard to track. Therefore, optical imaging-based activity trackers are not typically used for tracking exercise.
In light of the above, there is a need for improved systems and methods to accurately measure various characteristics associated with common physical activities, such as exercise.